A muscular sphincter regulating opening of oesophagus into the stomach is called:
(1) Pyloric sphincter
(2) Cardiac Sphincter
(3) Sphincter of oddi
(4) Boyden sphincter
(2) A muscular sphincter (gastro-oesophageal) regulates the opening of oesophagus into the stomach. Cardiac is the upper part of stomach into which the oesophagus opens, thus the sphincter is called as cardiac sphincter.